The effect of the nature of the anion in a palladium salt on a coupled process involving the oxida tion of CO and hydrocarboxylation of cyclohexene in the PdX 2 -CuBr 2 -THF-H 2 O system was studied. The kinetics was investigated under the steady state conditions. The kinetic isotope effects (H 2 O/D 2 O) for the rates of formation of CO 2 and cyclohexanecarboxylic acid were measured. The mechanism of the coupled processes of hydrocarboxylation of cyclohexene involving the formation of palladium hydride complexes and their transformations was suggested. The kinetic model of the processes was obtained. Conditions: THF, 30°C, [PdX 2 ] = 0.005 mol/L, [CuBr 2 ] = 0.015 mol/L, [C 6 H 10 ] = 0.9 mol/L, initial ratio CO : O 2 ~ 1 : 1.Fig. 4. Dependences of the formation rates of (a) CO 2 and (b) CHCA on [PdBr 2 ]. Conditions: THF, 30°C, [CuBr 2 ] = 0.015 mol/L, [H 2 O] = 0.6 mol/L, [C 6 H 10 ] = 0.9 mol/L, initial ratio CO : O 2 ~ 1 : 1.